vfs: spread struct mount - is_path_reachable

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -2559,21 +2559,21 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
  *
  * namespace_sem or vfsmount_lock is held
  */
-bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry,
+bool is_path_reachable(struct mount *mnt, struct dentry *dentry,
 			 const struct path *root)
 {
-	while (mnt != root->mnt && mnt_has_parent(real_mount(mnt))) {
-		dentry = mnt->mnt_mountpoint;
-		mnt = mnt->mnt_parent;
+	while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {
+		dentry = mnt->mnt.mnt_mountpoint;
+		mnt = real_mount(mnt->mnt.mnt_parent);
 	}
-	return mnt == root->mnt && is_subdir(dentry, root->dentry);
+	return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);
 }
 
 int path_is_under(struct path *path1, struct path *path2)
 {
 	int res;
 	br_read_lock(vfsmount_lock);
-	res = is_path_reachable(path1->mnt, path1->dentry, path2);
+	res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);
 	br_read_unlock(vfsmount_lock);
 	return res;
 }
@@ -2659,7 +2659,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
 	if (!mnt_has_parent(new_mnt))
 		goto out4; /* not attached */
 	/* make sure we can reach put_old from new_root */
-	if (!is_path_reachable(old.mnt, old.dentry, &new))
+	if (!is_path_reachable(real_mount(old.mnt), old.dentry, &new))
 		goto out4;
 	br_write_lock(vfsmount_lock);
 	detach_mnt(new_mnt, &parent_path);

fs/pnode.c

@@ -32,15 +32,15 @@ static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
 					    struct mnt_namespace *ns,
 					    const struct path *root)
 {
-	struct vfsmount *m = mnt;
+	struct mount *m = real_mount(mnt);
 
 	do {
 		/* Check the namespace first for optimization */
-		if (m->mnt_ns == ns && is_path_reachable(m, m->mnt_root, root))
-			return m;
+		if (m->mnt.mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))
+			return &m->mnt;
 
-		m = next_peer(m);
-	} while (m != mnt);
+		m = real_mount(next_peer(&m->mnt));
+	} while (&m->mnt != mnt);
 
 	return NULL;
 }

fs/pnode.h

@@ -42,6 +42,6 @@ void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
 void release_mounts(struct list_head *);
 void umount_tree(struct mount *, int, struct list_head *);
 struct mount *copy_tree(struct mount *, struct dentry *, int);
-bool is_path_reachable(struct vfsmount *, struct dentry *,
+bool is_path_reachable(struct mount *, struct dentry *,
 			 const struct path *root);
 #endif /* _LINUX_PNODE_H */